Commercial vehicles consist usually of a towing vehicle and one or more towed trailers. Such an articulated road train is called a motor vehicle with trailer; a semi-truck is referred to as a tractor engine and a semitrailer.
Parked and non-driven vehicles each can be secured against theft by mechanical devices. The motorized parts of the truck are in most cases also secured against theft, for example, by means of immobilizers or alarm devices. If both vehicle parts are coupled to each other, there is a certain theft protection through these systems for the entire semi-truck because decoupling is only possible by a movement of both vehicle parts relative to one another.
However, the number of thefts where the driven vehicle is separated from the trailer or semitrailer and subsequently stolen is constantly increasing despite the current technical aids. Thus, it is desired to provide devices and systems which prevent that the semitrailer can be decoupled without authorization or, at least, that this process is made difficult enough that the attempt to do so appears to be hopeless in the first place.
From WO 03/043838 A2 an anti-theft security device for fifth wheels is known which comprises an actuating device with a locking pin. The fifth wheel has a lock with a pawl which can be manually actuated via a linkage with a drawbar.
The anti-theft security device provides that the lock pin is inserted either in the movement path of the pawl or of the components of the linkage for actuating the pawl so that the pawl can not be moved from its closed position into an open position.
The anti-theft security device has a receiver through which the actuating device can be controlled. The anti-theft security device is coupled to a Global Positioning Device of the vehicle. If the vehicle is not driving on the intended route, this is recognized by the GP-System and a signal for arming the anti-theft security system is transmitted to the receiver whereupon the locking pin is brought into the locking position.
According to another embodiment, the anti-theft security device can also be controlled via internet by means of an externally arranged computer via the on-board computer of the towing vehicle.
Attempts to tamper at the fifth wheel are also recognized by the anti-theft security system which subsequently goes automatically into the armed position and thus into the locking position.
In WO 03/044627 of the same applicant, further security systems are described, wherein, among other things, the driver's authorization is checked through the input of a code. In case of non-compliance or deviation from the travel route, an automatic intervention in the vehicle functions takes place.
WO 2005/028290 A1 discloses a fifth wheel with an anti-theft security device in which a locking pin engages directly with the locking hook and locks the same. The locking of the door can be released via the drawbar. A forcible separation of tractor and semitrailer can not be prevented because in case of a jerky start of the semi-truck, the anti-theft security device can get damaged or even destroyed thereby turning the locking hook in the open position.
The anti-theft security device comprises a control device in the driver's cab of the tractor, in which control device a numerical code can be entered for activation. Further, sensors and displays are connected with the control device for monitoring the fifth wheel.
DE 195 16 101 A1 describes an anti-theft security device for a coupled semitrailer. To protect the semitrailer coupled to a tractor against theft by decoupling, the fifth wheel has a lock which controls an axially movable tappet. The tappet engages directly with the locking element of the locking hook when the same is in the locking position. The arrangement of the anti-theft security device is selected in such a manner that the tappet is pressurized when needed. The locking of the manually actuated locking hook has the advantage that in case of shocks or overloading the manual actuator, the elements of the manual actuators with weaker cross-sections break and the locking of the locking hook remains intact in any case. All parts of the anti-theft security device are subjected to compressive stress upon an attempt to unlock by force so that relatively small cross-sections provide the required functional safety.
From DE 295 01 043.6, an anti-theft security system for, among other things, semitrailers is known, which system is configured as electronic immobilizer. It is provided that upon activation of the anti-theft security device, i.e. in case of theft, the anti-theft security device influences the function of the tractor in such a manner that the same is blocked.
The known anti-theft security devices are either systematically activated, e.g. by the driver, and can only be deactivated by systematically entering, e.g., a numerical code.
However, there are emergencies in which the semi-truck has to be separated by emergency responders at the place of accident. In such cases, the driver might be unable to deactivate the anti-theft security device, or, the respective equipment for deactivating the anti-theft security device by the driver is not functioning anymore.
Separating the two vehicles is then possible only with major efforts and with adequate tools. This involves not only a considerable expenditure of time but it can also result in additional danger for the emergency responders and/or the road users, in particular if the semi-truck transports dangerous goods.